1. Field of the Invention
The present invention relates to a fungicide against a filamentous fungus which contains a compound produced by a microorganism belonging to the genus Enterococcus, as well as a method for its production and its usage.
2. Description of the Related Art
With regard to antifungal activity of microorganisms belonging to the genus Enterococcus there have been some studies reported. For example, Japanese Patent Laid-Open No. 97689/1993 discloses an infection protective agent which contains cells of microorganisms which belong to the genus Enterococcus or their treated material as an active component. Japanese Patent Laid-Open No. 263539/1997 discloses a therapeutic agent for dermatopathy which comprises lactic acid bacteria and their treated substances as active ingredients. These documents disclose that the strain used particularly in the Examples is Enterococcus faecalis NF-1011 which can be used as a fungicide against fungi such as Candida etc. Said documents disclose a usage of not the product by bacteria but bacterial cells themselves, that is, ingestion of dead bacterial cells, living bacterial cells, or fungus bodies that are processed by grinding, extracting with water etc.
Japanese Patent Laid-Open No. 300284/2000 discloses that phenyllactic acid produced by using lactic acid bacterium, that is, Enterococcus faecalis, has antibacterial activity. It also discloses that said phenyllactic acid shows a strong antibacterial activity against harmful microorganisms such as enterohemorrhagic E. coli O-157, methicillin-resistant Staphylococcus aureus (MRSA), etc. Moreover, anti-MRSA activity of Enterococcus faecalis TH10 is disclosed in Japanese Journal of Dairy and Food Science, vol. 45, No. 4, A93-96 (1996) and anti-E. coli O-157 activity is disclosed in Milk Science, vol. 49, No. 2, 81-86 (2000).
Each of said documents discloses that Enterococcus faecalis has antibacterial activity. Although they disclose that said microorganism is effective against bacteria such as O-157, MRSA, etc., and that it is effective against Candida, a fungus categorized in yeast, they do not disclose that it is effective against fungi categorized in filamentous fungi.
Filamentous fungi, particularly dermatophytes, are causative fungi of many dermatological diseases represented as so-called tinea. Agent with effective antifungal activity against dermatophytes has been longed for. Dermatophytes are dermatologic filamentous fungi which usually infect keratine tissues such as keratinocyte, hair and nails of mammals, including human. Dermatophytes are classified into the following three genera: Trichophyton, Microsporum, and Epidermophyton. According to the Epidemiological Investigation Committee for Human Mycoses in the Japanese Society for Medical Mycology, the incidences of tinea is reported to account for almost 100% with two species such as Trichophyton rubrum (70.5%) and Trichophyton mentagrophytes (26.8%) followed by Microsporum canis, Epidermophyton floccosum, Microsporum gypseum, Trichophyton glabrum and Trichophyton verucosum in order.
In spite of a wide range of usage of clinically effective fungicides such as imidazole compounds or antibiotics, requirements to a novel and effective fungicide that is free of any side effects have yet been longed for at present. On treatment of tinea, it is a fact that many patients are reluctant to use a synthetic medicine in view of safety since they need to use it repeatedly for a long time in many cases.
Moreover, there are some filamentous fungi that inhibit the growth of useful plants. For example, Rosellinia necatrix and Helicobasidium mompa grow in land around the roots of fruit trees etc. and inhibit their growth. Fusarium oxysporum and Pythium graminicola cause seedling disease of rice or the phenomenon of turf which is blasted locally, and Pyricularia oryzae causes blast of rice.
Many kinds of effective fungicides as represented with synthetic chemical compounds against filamentous fungi that inhibit the growth of plants are known. However, these chemical compounds may pose the risk to give harmful influence to the human body as residue in crops. They may also pose the risk to pollute the surrounding environment such as land and rivers. Therefore, a safe fungicide without such problems has been sought for.
The object of the present invention is to solve the above problem and to provide a safe and effective fungicide against filamentous fungi.